The Library is currently in the process of being upgraded from Oracle Database Version 12.1.0.1 to
12.1.0.2. Demos are being upgraded to reflect the new Container paradigm as well as EBR (Edition Based Redefinition) and may contain
references to CDBs, PDBs, and other objects you may not be familiar with such as CDB_OBJECTS_AE: Welcome to 12c.

According to the 8.1.5 online docs this package "Handles index-table operations." Note 1 on the same page states: "The DBMS_STANDARD, STANDARD,
and PLITBLM packages contain subprograms to help implement basic language features. Oracle does not recommend that the subprograms be directly called. For this reason,
these three supplied packages are not documented in this book." Blog posts indicate more specificaly the package contains the functions that can be utilized when working with Associative Arrays.

PLITBLM is a stand-alone package header (no body). The functionality it provides is defined with PRAGMA INTERFACE(C, ...)